Coda
From Halopedia, the Halo wiki
Summary
Small UNSC shuttle pod. Captain Keyes took the Coda when he personally inspected the Pillar of Autumn when he assumed command of that vessel over Reach in 2552. Keyes then docked the Coda in one of the Autumn's docking bays. The pod probably was still aboard when the Autumn crashed on Installation 04, and was then likely destroyed, either in the crash or the explosion that destroyed the Halo.